Makdaddynuge

I have a high idle problem on cold startup. It idles at around 3000 rpms and gradually goes down as the car warms up, so after about 5 minutes its at 1000-1200 rpms, which i think is still high for normal idle. Well, today i took my intake off and looked in the trottle body. Started the car, of course its at 3000rpms. There are 2 machined oval holes inside the trottle body opening on the left side both sucking in air (of course). I put my finger over the bottem one to plug it up and my idle went straight down to normal idle rpm. When i put my finger over the top hole it drops some, like 800-1000 rpms but not to normal. It seems that maybe that bottem hole is the answer to my problems. Does anyone know what the two holes are, especially the bottem one? And what they go to and can they lead me to my problem?

For background info, its a 1994 civic dx hatch. Car was an automatic before, we did the gsr swap (obd-2 motor) and auto to manual conversion. Still running stock gsr intake manifold. P28 chipped ecu.




Your suggestions/answers are greatly appreciated.


Modified by Makdaddynuge at 12:21 PM 9/1/2005


Modified by Makdaddynuge at 2:18 PM 9/1/2005

Makdaddynuge

bump....nobody knows? hopefully after 5 people getting off work will know

Makdaddynuge

bump...pics are up

dpetro1

bottom hole is fitv (fast idle thermo valve) i know many people have had problems with idle surge from the fitv but i dunno bout just i high idle. maybe though cause i believe that valve is there to use engine coolant to warm up the intake air, in turn warming the car faster. as for the top hole im not sure, iacv maybe?

Makdaddynuge

ok does that valve have a sensor or something that is supposed to regulate it or something?

Makdaddynuge

bump...gonna try and clean the fitv

dpetro1

i dunno bout the sensor but it probably wouldnt hurt to take the fitv apart and make sure its screwed down tightly. since you said you plugged the bottom hole and idle was normal i would say fitv is the culprit. here is a link to a good write-up
https://honda-tech.com/zerothread?id=699787

cerwin23

did you try and adjust your idle screw on your throttle body? try that. also, make sure you hose on your throttlebody (map sensor) is connected right.

Makdaddynuge

yeah thanks dpetro, i found that late last night and screwed it down. I didn't clean it thuogh. Now it idles around 1400 for cold start and after it warms up its around 1000 rpms and barely surges between 900-1100 rpms, so there is still something going on. I am gonna clean out my iacv and see if there is any air in my coolant system.

tsjeff

check your throttle body gasket

Makdaddynuge

we took the trottble body off last night and checked it...it looks fine...if all these other things i try fail, i will get a whole new intake manifold gasket and throttle body gasket and replace those.

mike1114

iTrader: (1)

spray carb cleaner over map, tps, and all gasket areas to see if you can find the leak, if the car stumbles or cuts out, you found where the vacuum leak is.

Makdaddynuge

cool that sounds easy, i'll try that

hatchi

also try putting on an intake tube w/filter see if that works

Makdaddynuge

like an aftermarket intake with filter? I already have one on.

EJK20R

I had the same problem when I start my car my idle was at 2500 and then goes down as the car was warming up I asked around and narrowed it to the FITV (fast idle thermal valve) that is the cause of all yoyur problems goto search and there should be a thread on the steps to fix the problem

Makdaddynuge

fixed that, it still is idles at 1100 and surging a little, so something still isn't right.

EJK20R

you might have to replace the IAC valve

Makdaddynuge

i cleaned it with carb cleaner, didn't do anything. Is there a way to check to see if its broken or something?

Archidictus

There are only two reasons you should ever have an erratic idle.

1.) your ECU or fuel system hardware is fucked up or
2.) much more likely - you have a vacuum leak somewhere. This could be pretty much anywhere on the intake side of the head, so check all the gaskets, replace them all if you have the cash and use the Helms to test all the TB and IM sensors associated with airflow.

Makdaddynuge

yeah i'm gonna try a virgin p28 see what that does.

SavEM1

are you throwing a code or what?

If you are going to be taking apart your IM you might as well and try to clean your IAC as well at the same time.....

siregcivic

hey.. i had surging idle problem for 2 months on my motor.... i tried everything .. fast idle valve new tb gasket.. well i bought throttle body and intake mani cleaner and sprayed it when the car was warm but off... all over the place.. in those 2 holes your talking about and everything.. i sprayed the whole can in there.. its fine now...

btw dont use carb cleaner its not safe for the o2 sensor.. use tb and intake manifold cleaner

Makdaddynuge

no check engine light. I already took the iacv off and sprayed the screen with carb cleaner